By Sophia Read
For The Bali Times
SEMINYAK ~ One of the main joys and attractions of scuba diving is the feeling of weightlessness that comes on a dive – the sensation of flying, suspended perfectly, unlimited motion in any direction. The key to this is good buoyancy, and, unfortunately, that does not come naturally.
Nearly every diver I have spoken to has a story to tell about a moment on their certification course where the instructor did one of the amazing maneuvers that humans can only do underwater or in space: turn upside down, and float motionless while peering under a rock; crosses their legs and assumes the Buddha position mid-water; rising and falling almost imperceptibly with each breath. In the meantime, most of us were clutching the low-pressure inflator hose (which puts air into and takes air out of your Buoyancy Control Device or BCD), and alternating between shooting for the surface and clanking down on the sea floor.
The main principle of buoyancy is that â€œAn object placed in water is buoyed up a force equal to the weight of the water it displaces.â€ Divers float by achieving neutral buoyancy through a variety of devices. Most people naturally float, and so does neoprene (of which the majority of wetsuits are made). So a human in a wetsuit will naturally float to the surface. To combat this, divers wear weight belts with lead weights, to sink. However, at increasing depth, water pressure increases, and air volume decreases, so divers use their BCD to compensate for these changes on ascent and descent.
At a constant depth, a diver with good buoyancy should not need to adjust the amount of air in their BCD. If you have good buoyancy, the main use for your BCD is to float you without effort, when on the surface waiting to ascend or descend.
Achieving perfect buoyancy control benefits the diver in many ways, not only by preventing damaging collisions with the marine seascape (damaging not only to the coral in most cases but to the diver as well). Good buoyancy will extend the length of your dives considerably. On most recreational dives, the time the diver spends underwater is only limited by the amount of air they have available, i.e. in the tank they carry. As movement underwater is minimalised by the ability to go directly where you want, rather than be constantly pulled up or down and having to kick to maintain your depth, you breathe less air. The air in the BCD comes directly from the tank, and is then not available for respiration. Constantly putting more air into the BCD, only to vent it almost immediately as the diver begins to shoot towards the surface, and then put more in as they plummet for the bottom â€“ well, you can imagine how much air that wastes.
Good buoyancy also increases your chances of great encounters with marine life, which tends to hang around longer if the diver can remain relatively motionless. Frantic bobbing up and down and kicking scares most creatures away. There are a few basic fundamentals involved, the first of which is a good buoyancy check at the start of the dive. Carrying no more lead than you actually need adds greatly to the enjoyment of your dive time. Proper placing of the weight that you do need is essential; weights in the wrong place, or placed unevenly, can lead to some very strange body positions underwater. Being streamlined also helps: having all your equipment proper clipped away, with no dangling hoses or instruments significantly decreases the effort that you need to move underwater, and thus, the amount of air that you breathe.
After all, diving is perhaps the only sport in the world where the majority of those who enjoy it spend all their time trying to use as little effort as is physically possible.
The writer is sales manager of AquaMarine Diving â€“ Bali.Filed under: The Island